Metal mold



'J. F. KELLER AL MOLD Oct. 21 1924.

2 Sheet .s -Sheet 1 Filed April 29, 1922 Inn y 1 N VEN TOR a ATTORNEY.

Oct-

! J. F. KELLER METAL MOLD Filed April 29, 1922 ZSheta-Sirnt' I/// Ag f INVENTOR.

UP ATTORNEY.

Patented Oct. 21, 1924.

UNITED STATES l ATENT OFFICE.

JOSEPH F. KELLER, OF NEW YORK, N. Y., ASSIG-NOR TO KELLER MECHANICAL EN- GINEERING CORPORATION, OF BROOKLYN, NEW YORK, A CORPORATION OF NEW YORK.

METAL MOLD.

Application filed Apri1 29, 1922. Serial No. 557,380.

being produced by subjecting the mold blank to pressure, sufficient to force the metal into depressed or intaglio markings in the punch.

Heretofore, the cost of making accurate metal molds, in the cavities of which the design is such that it is in relief, has been very considerable because it has been necessary to accurately engrave the required design or markings in the cavity of the mold. here a large number of molds of this character are required, as is often the case, it will be seen that the cost of duplication by the engraying method becomes very considerable.

Therefore, the object of my improvement is to materially reduce the cost of hollow metal molds, such for example as are required in making golf balls or the like, by

forming the finished mold with the required markings in relief in the cavity thereof, by subjecting the mold blank to great pressure between a suitable die and punch whereby the metal is not only condensed, but is forced into the intaglio designs formed on the punch. This operation produces a highly finished surface on the interior of the cavity of the mold and; hardens and condenses the eta o th t a mold of per r quality produced.

In order to facilitate the formation of metal molds of this charactenunder pressur e ,with a punch and die, it will be understood that it would be impossible to withdraw the punch from the finished moldunless it were made collapsible and so far as I am aware,

by enabling me. to produce duplicate metal molds in large, quantities, each with a deeply recessed cavity in which the pattern or markings are formed in relief.

One form of my improved apparatus or punch and die for forming hollow metal molds, together with one of the molds is shown in the. accompanying drawings, in which Fig. 1 represents a sectional view in side elevation of the punch and die with the mold blank in place before pressure has been applied and Fig. 2 is a transverse view of the collapsible punch on the line 22 of Fig. 1; Fig. 3shows, in elevation, a crosssectional view of the punch and die with the mold under pressure therein; Fig. 4 shows a top plan view of the mold blank; Fig. 5 is a sectional view of the mold blank; Fig. 6 is a top plan view of the finished mold and Fig. 7 is asectional view of the finished mold of Fig. 6.

For the purpose of illustrating my improved means for forming hollow metal molds, I have preferably illustrated a mold for golf balls. It will be understood, however, that the same method may be followed for producing a greatvarie-ty of hollow molds, in which various designs may be formed on the surface of the cavity of the mold to be reproduced on the article molded therein.

Referring to the drawings, 1 represents the bed plate of a press and 2 the plunger thereof. The die and punch for forming my improved metal mold may preferably be mounted respectively upon the bed and plunger of the usual or any ordinary power press, adapted to bring the punch and die together with the required amount of pressure. As will be seen in Figs. 1 and 3 of the drawings, the die comprises a block 3, in which a conically shaped hole or recess 4; is formed, the narrow end of which joins, about mid-way of the thickness of the block, with a cylindrical. hole 5, in which is located a plug 6. The plug 6 is adapted to receive the thrust of the metal mold and limit its movement into the die under the pressure of the punch. The plug 6 and die block 3 are preferably secured together by. a wedge key 7 passing through a slotted hole 8 (see Fig. 1) in the block 3, and a correspondingslotted hole 9 in the plug 6.

The mold blank for forming molds for golf balls is shown in Figs. l and 5 of the drawings, from which it will be seen that the mold blank 10 is formed frusto-conical in shape on the outside at 11, and the base of the cone is provided with a hemispherical cavity or recess 12, having approximately the diameter of the finished mold, but with the inner surface smooth, substantially as illustrated in Figs. 1 and 5.

The angle of the outer conical surface 11 of the mold blank, with respect to the axis thereof may be slightly greater than the corresponding angle between the conical surface 4: and the axis thereof in the die 3 or the diameter of the frustum of the cone of the mold blank may be slightly greater than the corresponding diameter in the die cavity 1, so that the mold blank will occupy about the position indicated in Fig. 1 of the drawings, beforepressure has been applied thereto.

' The mold blanks 10 may be cast in the form indicated from any suitable metal or alloy, such as aluminum, brass or the like, which has the property of flowing when sufficient pressure is applied thereto. In molds of this character where there is a design or prearranged markings are essential on the finished surface of the article molded therein, it is obvious that the reverse of the design required must be formed on the interior surface of the cavity of the mold. Such a design as would form dimples, for

instance, on the finished golf ball would project radially and be in relief, as shown at 13, in the cavity of the mold, as illustrated in Figs. 6 and 7 of the drawings. The resulting golf ball molded therefrom will be provided with dimples or depressed markings. Obviously, it would be impossible to form the finished mold with the mark ings in relief on the surface of the cavity of the mold, as shown in Figs. 6 and 7 by forcing into the mold blank 10, a punch of ordinary construction, for it would be impossible, after the metal had been raised to form the design, for the punch to be withdrawn from the mold. Therefore, I have provided a collapsible punch for this purpose.

By reference to Figs. 1, 2 and 3 of the drawings, it will be seen that the punch, which is indicated as mounted upon the plunger bed plate 2, comprises a block 14 with a central hole 15, in which is located a plug 16, the upper end of which is of conical shape as shown in Figs. 1 and 3 of the drawings. The head of the punch is made up of a plurality of members which are held in operating position by the'conieal end 17 of the plug 16, as shown in the drawings. Thecollapsible punch, as illustrated in section in Fig. 2 of the drawings, comprises three parts 18, 19 and 20, forming substantially the complete circumference of a circle and these members are adapted to be wedged into place by a narrow member 21, as indicated in Fig. 2 of the drawings. The members 18 to 21 inclusive, are provided with conical surfaces on their inner face to cooperate with the conical plug member 17 and are provided with conical surfaces 22 on their outer faces to cooperate with. a conical hole in a ring or block 23, the arrangement being such that when the plug 17 is forced home by means of a. wedge 24, the members 18-21 are held firmly in the position indicated in Figs. 1 and 3 of the drawings. Cooperating with the members 1821, and forming the hemispherical end of the punch, is a member 25, which is provided with a recess at 26, cooperating with corresponding projections or shoulders on the members 18-21 so that they will all be locked together when the wedging plug 17 is w forced home. A pin 27 and socket are provided for properly locating the member 25 with respect to the members 1S-21, so as to maintain the continuity or proper registration of the design. It will. be seen that the member 25 of the punch does not extend for the full hemisphere but only far enough to permit it to be readily withdrawn from the finished mold, after the latter is formed under pressure, without spoiling the relief design formed therein. The balance of the hemispherical design is formed at 28, on the punch members 18-21, as indicated in Figs. 1 and 3 of the drawings. By this con struction, it will be readily understood that, after the blank 10, as shown in Figs. 4c and 5 of the drawings, is placed in the position shown in the Fig. 1, the head of the punch 25 and 28 will enter the cavity 12 and then, when suflieient pressure is applied, the mold block 10 will be forced into the conical die 4. to the position shown in Fig. 3 of the drawings and the metal of the mold will be forced to flow into the depressions or dimples formed in the surface of the punch members and 28 to reproduce, in relief, the intaglio design of the punch.

After the metal mold has been formed in the press, as shown in Fig. 3 of the drawings, it then remains to withdraw the collapsible punch 25-28 from the finished mold without destroying the relief desi n formed therein. This is accomplished y first withdrawing the conical plug 17, after which the wedging member 21 may be read ily removed, and following this, the remain ing members 18, 19 and 20, forming the peripheral portion 28 of the mold, may be removed and finally the end section 25 of the punch can be Withdrawn. All of the parts of the collapsible punch, it will be seen, can thus be removed. without eflucing or injuring the inner surface of the cavity of the mold; and it is found in practice that the molds produced by this method are of superior quality, in that the metal is condensed and hardened and the surface of the cavity of the mold is smooth and hard. And duplicate molds can be produced in large quantities at a minimum cost.

lVhile I have shown one form of collapsible punch for carrying out my improved method of forming hollow metal molds, in a power press, it will be understood that I do not wish to be limited to the form shown, for various modifications in the details of construction may be made for accomplishing the same results. The shape and construction of the die may also be changed, and various other modifications may be made without departing from the spirit and scope of the invention.

1 claim 1. An apparatus for forming a metal mold from a mold blank, comprising a die, into which said mold blank is adapted to be forced, a punch adapted to enter said die, the head of said punch being shaped to form the cavity of the mold with markings in relief, by compressing the inner surface of said blank and forcing the metal into cavities in the head of the punch, and means for separably removing said punch from the die after the mold is formed.

2. The apparatus as claimed in claim 1, in which the die cavity is frusto-conical in shape and the punch entering the cavity is of corresponding frusto-conical shape and comprises a plurality of separable parts wedged together.

3. In an apparatus for forming a metal mold, the combination of a die having a cavity, a collapsible punch, the face of which is provided with depressed or intaglio markings of the pattern to be reproduced in relief in the cavity of the mold and means effective after a mold blank has been placed between the punch and die for forcing the mold blank into the cavity of said die, whereby the metal of the mold is condensed and portions thereof forced into the depressions of the punch to thereby reproduce the markings in relief in the cavity of the mold.

4;. A punch and die for producing markings in relief in the cavity of a metal mold by forcing the metal into the pattern under pressure, which comprises a die provided with a frusto-conical cavity, in which the mold blank is placed, a collapsible punch comprising a plurality of members adapted to be wedged and held in position by a central conical plug in cooperation with a block provided with a concentric conical hole, the face of said punch being provided. with depressed markings, and means for forcing the punch into the die a predetermined distance whereby the metal of the mold blank is forced into the depressed markings on the face of the punch to thereby reproduce the design in relief in the cavity of the mold.

5. A punch and die for producing a metal mold having relief markings in a recessed cavity, which comprises a frusto-conical die into which the mold blank is forced, a collapsible punch for forcing the mold blank into the die, the collapsible head of said punch being provided with depressed markings, corresponding to the relief markings to be reproduced in the cavity of the mold, means for forcing the punch and the mold blank into the conical die, the pressure being sufficient to force the metal of the mold blank into the depressed markings of the punch, whereby the metal of the mold is condensed and the markings are reproduced in relief, and means permitting collapsing and removing the parts of said punch from the cavity of the finished mold.

6. A metal mold formed from a blank, cast or otherwise formed with a mold cavity extending the-reinto, said cavity being provided with markings in relief and having its inner surface hardened by pressure.

JOSEPH F. KELLER. 

